Provided herein are injectable, thermoresponsive hydrogels that are liquid at room temperature, provide a carrier material, and gel at body temperature to allow for controlled release. In particular, PPCN-based hydrogels are provided with therapeutic agents (e.g., drugs, ions, etc.) incorporated within or appended thereto, and methods of preparation and use thereof, for example, for the promotion of bone formation/repair and/or the treatment of bone diseases.